Originally Posted by 1stHD
I wonder how the ceiling fans will affect the sound system especially those on not-too-high ceilings. The wave from low frequency surely will push the blades and those blades will viberate. I have a 52" ceiling fan on 8' ceilings just a few feet in front of the main speakers.
SSpivey has this right.
Also, your question assumes that the blades of the ceiling fan have a resonant frequency that will be excited by low frequencies from your speakers/subwoofer.
In my expereience, other things in the room will be vibrating before a ceiling fan.
Which parts of the ceiling fan do you think will be vibrating? The mounting? The shaft? The blades? Since all of these parts are connected, who knows what the resonance frequency of the entire ceiling fan is?
Those 52 inch blades have a good amount of mass.
Like SSpivey said, turn the fan off for critical listening to avoid the normal swishing sound of the fan. Other than that, I think you would be hard pressed to excite the fans resonant frequency enough to be audible.
It's a shame that Bruce Thigpen can't figure out a way to turn an ordinary ceiling fan into one of his "flat to 1 Hz" Rotary Subwoofers for about 10% of the cost of the TRW-17.